When you observe some object from a rotating frame(The object is stationary in an inertial frame),what direction do we take the centrifugal force to act? Since the acceleration of our frame is constantly changing in direction does the direction of centrifugal force also keep changing? Also please explain the terms in the formula as im not very sure which 'r' to use

centrifugal force=pseudoforce

centrifugal force is always acting outside so no change.

therefore there will be no change in the centrifugal force

when you are talking about any frame of reference and the body is at rest...then there is no force actiong on it...not even the centrifugal one.  But when we talk about a rotating frame of referance, then the object, which is stationary with respect to the frame IS experiencing a PSEUDO force.This Pseudo force is opposite to the direction of the accelaration of the frame.

and YES the direction of PSEUDO force does changes if the inertial frame is a rotating one.But since there is no centrifugal force there is no change in it''s direction( how can it change when it does not even exist!)

Pseudo force = mass of the body  X accelaration of the frame of referance